The Destruction Of The Ozone Layer Essay

, Research Paper

INTRODUCTION

In the beginning man lived simply and harmoniously with earth. However, as time progressed mankind’s thirst for knowledge and more economical ways of doing things led to technological advances. These advances, in turn, led to the industrial revolution, the invention of the automobile, and growth of the automobile industry. Though making life on earth more comfortable, these industries and inventions emitted harmful gases into the earth’s atmosphere. Damage to the earth’s ozone layer began to occur as the levels of these gases in the atmosphere increased. The depletion of the earth’s ozone and the resulting greenhouse effect are now threatening the ability of earth to sustain civilization as mankind knows it today.

THE OZONE DEFINED

Ozone is a dark blue gas which is highly reactive. It’s triatomic molecular composition (O3 ) is unlike normal oxygen as it has an extra oxygen atom in each molecule and a different atomic arrangement.(Jones et al.303-304) In the earth’s upper atmosphere, called the stratosphere, O3 is produced when the sun’s ultraviolet rays act on normal oxygen in the air. Extending from 10 kilometers (km) to 50 km above the earth, the stratosphere has the highest concentration of ozone.(EPA, Ozone vs. Altitude 1) This is what is normally known as the “ozone layer”. The ozone layer serves a vital purpose in the stratosphere as it blocks out harmful ultraviolet rays. Ozone also occurs in lower amounts in the troposphere, which is the atmospheric layer lying between the earth’s surface and the stratosphere. Known at this altitude as smog, this ozone forms when the sun’s ultraviolet rays strike oxygen which has mixed with industrial or automobile pollutants.(EPA, Ozone Science 1)

THREATS TO THE OZONE

Man-made chemicals, fossil fuels, industrial wastes, and automobile exhaust all pose a threat to the earth’s ozone. Chlorofluorocarbons (CFCs) are man-made substances which, for more than 50 years, were considered to be miracle substances because they were virtually non-toxic, nonflammable, and inexpensive to produce.(EPA, Ozone Science 1-2) These CFCs were used as solvents, refrigerants, aerosol propellants, and to blow foam plastics. Due to their stable nature, CFCs remained intact for long periods of time in the atmosphere. Over time, winds have transported them into the stratosphere where they have been subjected to high levels of radiation. The radiation causes the CFCs to break down and release chlorine. According to the National Safety Council’s Environmental Health Center, “A single chlorine atom can destroy thousands of ozone molecules before it is eventually neutralized.”(3) Since the break down of CFCs is repetitive in nature it has the potential of severely depleting stratospheric ozone.

Nitrogen oxides and methane are also compounds which adversely affect the stratosphere’s ozone. Nitrogen compounds are used in agricultural fertilizers wheras nitrous oxide is produced by combustion. Methane is produced by a biological reaction between bacteria and organic matter. It is given off by cows, marshes, landfills, and garbage dumps.(Schneider 21, 101) Both substances are stable and react similar to CFCs in the stratosphere to deplete the ozone.

Fossil fuels are the world’s largest energy source. They are naturally occurring carbon or hydrocarbon fuels including oil, coal, and natural gas. These fuels are used to heat homes and businesses as well as power industrial equipment and automobiles. One of the endproducts of the combustion of these fuels is carbon dioxide (CO2). Carbon dioxide and the other byproducts of burning fossil fuels contribute to the build-up of ozone or smog in the troposphere. High levels of smog over urban areas such as Los Angeles can have detrimental effects on humans and plant life. Carbon dioxide has the ability to absorb high amounts of infrared energy, thus producing heat, and thereby warming the atmosphere.(Schneider 13-35) Efforts to decrease smog are also increasing the amount of harmful gases in the upper atmosphere. An article in the newspaper quoting the EPA stated that, “the catalytic converter, designed to scrub smog out of automobile exhaust, is spewing greenhouse gases from tailpipes into the upper atmosphere. The converters, while breaking down smog-causing nitrogen and oxygen from car exhaust, are also rearranging the compounds to form nitrous oxide..which is more than 300 times more potent than carbon dioxide.”(Lansing State Journal A1)

THE GREENHOUSE EFFECT

The greenhouse effect is the gradual rising of the lower atmosphere’s air temperature due to an accumulation of greenhouse gases. These gases, CFCs, CO2, methane, nitrous oxide, and ozone, form an invisible ceiling in the troposphere. This ceiling absorbs harmful radiation from the sun and prevents the loss of energy while allowing visible light to enter. This process helps to maintain a steady temperature on the earth.(Jones et al. 192)

Advances in technology, increased industrialization, and the proliferation of automobiles has led to an artificial build-up of greenhouse gases in the atmosphere. The thinning of the ozone layer in the stratosphere has allowed more harmful ultraviolet radiation to enter the upper atmosphere. The overabundance of these gases, particularly CO2, in the lower atmosphere, has led to increased absorption of infrared radiatio